Tow behind steerable caddy trailer

ABSTRACT

A steerable caddy trailer is provided that has an improved structure including a main frame assembly, spindle assemblies attached to each end of the main frame for attachment of a wheel, a pair of swinging arms forwardly extending from the main frame and pivotally attached to the main frame, and tie rods connecting the swinging arms with the spindle assembly such that pivoting of the swinging arms steers the wheels.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation of U.S. application Ser. No. 12/964,299 filedDec. 9, 2010, now U.S. Pat. No. 9,022,409 and will issue May 5, 2015,which is a Continuation of U.S. application Ser. No. 11/286,654 filedNov. 23, 2005 now U.S. Pat. No. 7,874,570 issued Jan. 25, 2011, whichthe applications are hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

The invention generally pertains to trailers and specifically totrailers designed for a tight turning radius.

Prior art trailers have been designed which provide a tight turningradius; however, these trailers use complicated structures to turn thetrailer's wheels.

U.S. Pat. No. 1,600,635, issued to Isachsen on Sep. 21, 1926, shows anarrangement of a frame 11, and a steering rod 7 independent of the frame11. The steering rod 7 is fastened to crank arm 3, then secured to aknuckle joint 4, and connected to a second knuckle joint 4′ using arms 5and a connecting bar 8. This complicated structure functions to turn thewheels 10.

U.S. Pat. No. 2,450,215 issued to Wilson on Sep. 28, 1948, uses multiplearms and steering links 29 and 14. This complicated structure functionsto turn the wheels 24.

U.S. Pat. No. 2,092,683, issued to Stidham on Sep. 7, 1937, shows anon-conventional system using parallel cable 32 and a draw frame system21. These two systems must operate together in order to turn the wheels14.

The above-subject patents are all structures which function to permitthe wheels to turn on stub axles. Unfortunately, each is a complicatedstructure and includes multiple moving parts.

Therefore, there is a need to produce a simplified structure with fewermoving parts to reduce costs associated with manufacturing, tooling andassembly.

Additionally, the complicated structures limit the amount of weight thatmay be placed upon them. Accordingly, it is a still further objective ofthe present invention to provide a trailer that may have a high maximumpayload for hauling a great amount of weight associated with farmproducts such as spray tanks, fertilizer, and seed.

These and other objectives will become apparent from the followingspecification and drawings.

BRIEF SUMMARY OF THE INVENTION

The foregoing objectives may be achieved using a tow behind steerablecaddy trailer having a main frame assembly having opposite ends, a wheelpivotally attached to each end of the main frame assembly, a pair ofswinging arms pivotally attached to the main frame assembly andextending forward from the main frame. The swinging arms are spacedapart from one another such that each swinging arm is positionedadjacent a wheel. The swinging arms can be maintained parallel ornon-parallel to one another. The trailer has a support structureattached to the main frame assembly that can support a platform, tank,hopper, etc. Additionally, it has been contemplated that tracks could beused in place of the wheels for supporting platforms, tanks and hoppersexceeding the weight limits for a wheel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a tow behind steerable caddy.

FIG. 2 is a top view of the tow behind steerable caddy.

FIG. 3 is a side view of the tow behind steerable caddy.

FIG. 4 is a rear view of the tow behind steerable caddy.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIGS. 1-4, numeral 10 refers to a tow behind steerablecaddy. The tow behind steerable caddy trailer 10 is designed to followbehind a tractor, an implement pulled by a tractor, or other vehicle.

The trailer 10 is designed to follow in the tracks of the towing vehicleto navigate tight turning radiuses. The tow behind steerable caddytrailer 10 thus may negotiate tight turning radiuses in a field withvery few end rows or with equipment that has a very narrow operatingwidth.

The steerable caddy trailer 10 has a main frame assembly 12 illustratedas a metal square tube. The main frame assembly 12 has opposite ends 14,a top side 16, a bottom side 18, a front side 20, and a back side 22.Angled end caps 26 are attached at each end 14 of the main frameassembly 12. It has been contemplated that the end caps 26 could also bea vertical endcap rather than an angled endcap 26. A vertical endcap maybe used in conjunction with a track or in applications requiringadditional structural strength to support heavy loads.

A spindle assembly 28 is pivotally attached at each end 14 of the mainframe assembly 12. The spindle assembly 28 has a base plate 30 and a topplate 34 connected by an angled extension 36 which ends in a verticalsurface with a spindle 40 for a wheel 44.

The base plate 30 and top plate 34 are attached to the angled end cap 26by a pivot pin 42. The spindle assembly has a vertical support 38 whichstrengthens the connection of the base plate 30 and the top plate 34 tostrengthen the spindle assembly 28.

A forward base member 32 is provided to extend from the base plate 30and has a hole for connecting a first end of a tie rod 70.

Swinging arms 46 extend from the main frame assembly 12. Each swingingarm member 46 has a rear end 48 that pivotally attaches to the mainframe assembly 12. The rear end 48 has a top support 50 and a bottomsupport 52, which extends above and below the main frame assembly 12 topivotally attach to a cylinder 54 at the back side 22 of the main frameassembly 12 by a pivot pin 61. The bottom support 52 also has a hole forreceiving a front end of tie rod 70. A front end 58 of the swinging armmembers 46 has an adapter 60 for attaching to a rigid cross member, suchas the exemplary rigid cross member shown in FIG. 1 in dashed lines. Therigid cross member could be a piece of square tubing (as shown). Therigid cross member could also be a bumper, a vehicle, a tractor or otherfarm implement. It is preferred that the swinging arm members 46 bepivotally mounted to a rigid cross member. For example, attaching ahitch to the adapter 60 and a ball to both ends of the rigid crossmember (as shown in FIG. 1 in dashed lines) allows the swinging armmembers 46 to pivot about the balls. Similarly, swinging arm members 46could also be pivotally attached to a bumper or another rigid crossmember as part of a farm implement.

In FIG. 1, the swinging arm members 46 are shown parallel to each otherand the tires 44 are shown perpendicular to the main frame assembly 12.However, the swinging arm members 46 need not be parallel to each otherfor the trailer 10 to steer. Adjusting the swinging arm members 46affects the turning radius of the steerable caddy trailer 10. Regardlessof the configuration, whether the swinging arm members 46 are parallelor moved inward closer to each other, the tie rods 70 can be adjusted tokeep the tires perpendicular to the main frame assembly 12.

A platform support 62 is provided that has side supports 64 and a frontsupport 66 connecting the two side supports 64 and sub-platform supports68. The platform support 62 balances the weight of a platform, tank,hopper or other evenly towards the front and back of the main frameassembly 12.

In operation, the caddy is pulled behind the implement and/or vehicle bypivotally connecting the swinging arm members 46 to a rigid crossmember. Should the towing vehicle or farm implement turn left this willsimultaneously cause the left swinging arm 72 to shift rearward towardthe main frame assembly 12 and the right swinging arm 74 to shiftforward away from the main frame assembly 12. Shifting the left swingingarm 72 rearward towards the main frame assembly causes the tie-rodlinkage 70 to move the spindle assembly such that the left wheel 76steers right. Similarly, shifting the right swinging arm 74 forward awayfrom the main frame assembly causes the tie-rod linkage 70 to move thespindle assembly such that the right wheel 78 steers right, also. Thus,when the towing vehicle turns left the wheels 44 on the steerable caddy10 turn right so as to track the towing vehicle.

Should the towing vehicle or farm implement turn right this willsimultaneously cause the left swinging arm 72 to shift forward away fromthe main frame assembly 12 and the right swinging arm 74 to shiftrearward toward the main frame assembly 12. Shifting the left swingingarm 72 forward away from the main frame assembly causes the tie-rodlinkage 70 to move the spindle assembly such that the left wheel 76steers left. Similarly, shifting the right swinging arm 74 rearwardtoward the main frame assembly causes the tie-rod linkage 70 to move thespindle assembly such that the right wheel 78 steers left, also. Thus,when the towing vehicle turns left the wheels 44 on the steerable caddy10 turn right so as to track the towing vehicle.

In either instance after the towing vehicle turns left or right andreturns to driving a straight course, the wheels 44 return to a positionperpendicular to the main frame assembly 12. In this fashion, thesteerable caddy trailer is maintained in virtually the same turningradius as the vehicle and/or implement.

The invention has been shown and described above with the preferredembodiments, and it is understood that many modifications,substitutions, and additions may be made which are within the intendedspirit and scope of the invention. From the foregoing, it can be seenthat the present invention accomplishes at least all of its statedobjectives.

What is claimed is:
 1. A method of steering a trailer comprising:providing a main frame assembly having opposite terminal ends withspindles and pivotally attached wheels, a pair of swinging armattachments rotatable about the main frame assembly and disposed onopposing sides of the main frame assembly between the terminal ends ofthe main frame assembly, a pair of swinging arms each having opposingterminal ends, the pair of swinging arms attached to the pair ofswinging arm attachments at opposing angles relative to the main frameassembly, and a tie rod having a first end connected to the swinging armattachment of the adjacent swinging arm and a second opposite endconnected to each wheel, wherein each one of the pair of swinging armsare attached at separate points to both the main frame assembly and tierod; attaching forward ends of the swinging arms to a towing implement;steering the trailer through a turning radius by translating oppositeturning forces from the towing implement through the pair of swingingarms; and changing the turning radius by increasing one of the opposingangles and decreasing the other one of the opposing angles between themain frame assembly and the pair of swinging arms.
 2. The method ofclaim 1 further comprising narrowing the turning radius by positioningthe swinging arms so the opposing angles are generally 90 degrees. 3.The method of claim 1 further comprising widening the turning radius bypositioning the swinging arms so the opposing angles are generallyacute.
 4. The method of claim 1 further comprising adjusting a length ofeach tie rod to align the wheels generally perpendicular to the mainframe assembly.
 5. The method of claim 1 further comprising steering thetrailer to the right by decreasing the opposing angle between the leftside swinging arm and the main frame assembly and increasing theopposing angle between the right side swinging and the main frameassembly.
 6. The method of claim 1 further comprising steering thetrailer to the left by increasing the opposing angle between the leftside swinging arm and the main frame assembly and decreasing theopposing angle between the right side swinging and the main frameassembly.
 7. The method of claim 1 wherein the attaching step comprisesattaching forward ends of the pair of swinging arms to the towingimplement whereby the opposing angles and equal.
 8. A method foradjusting steering of a trailer comprising: providing a pair of swingingarms each having a forward an rearward end, a main frame assembly havingopposite terminal ends with spindles and pivotally attached wheel, apair of swinging arm attachments rotatable about the main frame assemblyon opposing sides of the main frame assembly and spaced between theterminal ends of the main frame assembly, the rearward end of eachswinging arm attached to the pair of swinging arm attachments, and a tierod having a first end connected to the swinging arm attachment of theadjacent swinging arm and a second opposite end connected to each wheel,wherein each one of the pair of swinging arms are attached at separatepoints to both the main frame assembly and tie rod; establishing aturning radius for the trailer by adjusting the angle between eachswinging arm and the main frame assembly; and attaching the forward endsof the swinging arms to a towing implement at the adjusted angle betweeneach swinging arm and the main frame assembly.
 9. The method of claim 8further comprising narrowing the turning radius by adjusting the anglebetween each swinging arm and the main frame assembly to generally 90degrees.
 10. The method of claim 8 further comprising widening theturning radius by adjusting the angle between each swinging arm and themain frame assembly to less than 90 degrees.
 11. The method of claim 8further comprising aligning the wheels perpendicular to the main frameassembly by lengthening or shortening the tie rods.
 12. A method forsteering a caddy trailer comprising: providing a main frame assemblyhaving opposite terminal ends adapted for carrying spindles withpivotally attached wheels, a pair of swinging arm attachments rotatableabout the main frame assembly on opposing sides of the main frameassembly and spaced apart from the terminal ends of the main frameassembly, a pair of swinging arms attached at an angle to the pair ofswinging arm attachments, and a tie rod having a first end connected tothe swinging arm attachment of the adjacent swinging arm and a secondopposite end connected to each wheel, wherein each one of the pair ofswinging arms are attached at separate points to both the main frameassembly and tie rod; attaching forward ends of swinging arms to atowing implement for transferring a towing force to the main frameassembly; and steering the wheels left and right using turning forcesfrom the towing implement by changing the angle between the pair ofswinging arms and the main frame assembly in equal and oppositeproportions.
 13. The method of claim 12 further comprising steering thewheels to the right by decreasing the angle between the left sideswinging arm and the main frame assembly and increasing the anglebetween the right side swinging and the main frame assembly.
 14. Themethod of claim 12 further comprising steering the wheels to the left byincreasing the angle between the left side swinging arm and the mainframe assembly and decreasing the angle between the right side swingingarm.